Yeah, I'm prone to go down rabbit holes looking at the etymology and origin of related words for hours. Latin was one of my favorite classes in high school. It's great for world building and stylizing prose when writing fiction.

Sometimes the etymology is just weird because the current meaning is from an abbreviation of a phrase and the roots don't make sense in isolation, such as perfidious, from the roots per fidem "through faith" but its meaning is from the larger phrase "deceiving through faith."